Need help
 

ok so is 彼 a common way to use this sentence? 彼は背が高いです。and if not what is the best way to say that referring to he/she thats not there?

The only place in Japan where you will hear 彼は背が高いです is the English class in junior high school where someone has to translate "He is tall." into Japanese. We seldom use pronouns.

We would say:

あの人は背が高い（です）。

あいつは背が高い。(highly colloquial) Don't use this unless you understand the nuiance of あいつ.